Give expression in both tuple calculus and domain calculus, Database Management System

Assignment Help:

Consider the following relational schema:
Doctor(DName,Reg_no)
Patient(Pname, Disease)
Assigned_To (Pname,Dname)
Give expression in both Tuple calculus and Domain calculus for every of the queries:
(i) Get the names of patients who are assigned to more than one doctor.
(ii) Get the names of doctors who are treating patients with ‘Polio'.

Ans:
(i)Tuple Calculus:
{p[PName] | p ∈ PATIENT ∧ ∃a1, a2 (a1 ∈ ASSIGNED_TO ∧ a2 ∈ ASSIGNED_TO ∧
p[PName] = a1[PName] ∧ a1[PName] = a2[PName] ∧ a1[DName] ≠ a2[DName])}
Domain Calculus:
{p | ∃p1, d1, p2, d2 ( ∈ PATIENT ∧ ∈ ASSIGNED_TO ∧
ASSIGNED_TO ∧ p1 = p2 ∧ d1 ≠ d2)}
(ii)Tuple Calculus:
{u[Dname] | u ∈ ASSIGNED_TO ∧ ∃t (t ∈ PATIENT ∧ t[Disease] = ‘Polio' ∧
t[PName] = u[PName])}
Domain Calculus:
{d | ∃p1, p2, s2 ( ∈ ASSIGNED_TO ∧ ∈ PATIENT
∧ p1 = p2 ∧ s2 = ‘Polio')}


Related Discussions:- Give expression in both tuple calculus and domain calculus

Determine the advantage of object-orientation, Determine the advantage of o...

Determine the advantage of object-orientation Finally, object-orientation has advantage of continuity throughout analysis, persistent representation and design implementation.

Computer, what is object-identity

what is object-identity

What are the drawbacks of shadow-paging technique, What are the drawbacks o...

What are the drawbacks of shadow-paging technique? The drawbacks of shadow paging is:- a) Commit Overhead b) Data fragmentation c)  Garbage collection

Describe dynamic model, Describe Dynamic Model. The dynamic model speci...

Describe Dynamic Model. The dynamic model specifies allowable sequences of changes to the objects from an object model. It contains event trace diagrams describing scenarios. A

Discuss the method for a hash file to expand shrink dynamic, Discuss the me...

Discuss the methods for a hash file to expand and shrink dynamically. What are the advantages and disadvantages of each? The hashing methods that permit dyanamic file expansi

What is the meaning of recovery, What is the meaning of Recovery? In d...

What is the meaning of Recovery? In deferred update methods, if a transaction fails before arriving its commit point, it will not have altered the database in any way, so UNDO

What are wait-for-graphs, What are wait-for-graphs?Give the algorithm to co...

What are wait-for-graphs?Give the algorithm to construct a wait-for-graph from a given schedule of transactions? How can deadlocks be detected from wait-for-graphs?   Ans:  The

Special workarea for interface, While using extract datasets it is required...

While using extract datasets it is required to have a special workarea for interface False.  It is not required to have a special workarea for interface

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd